Has anyone had trouble with speed on their tt

Drubin,

It's a vicious circle. We have yet to define speed stability. There seem to be various camps when it comes to the finer points of that definition.

I'll say this much; I believe it is a relatively narrow field.

Syntax is right.

Moonglum, you are correct, except you dismiss the possibility of a turntable that can pass the Timeline test without servo controls and still involve the listener in the performance.

Read Doug Deacon's last post again. He gets it.

Zavato said, "stick with a design that has an AC synchronous motor and a platter heavy enough to have some flywheel effect."

I could not disagree more. Flywheel effect caused by the platter is the reason many turntables lack micro dynamics, or sound lackluster in more general ways. It is a simple case of letting the platter control the speed, rather than the device assigned the job, the motor. That doesn't work, if you want a turntable that is truly precise.

Correct, Tony.

Except...

System inertia is key here, and certainly not platter flywheel effect like some turntable designers would have you think. I like high mass platters, but where the mass is located is critical, in my opinion. If properly done, the platter can be an extremely important component toward reaching the goal of optimal system inertia. I realize that my view goes against conventional thought on the subject, but I am convinced that the location of platter mass is a big deal.

One day maybe people will see that a platter should be more than a big round chunk of whatever, but right now there seems to be little thought put into platter design. Guys use a lot of different materials in lots of different combinations, but in the end they are still nothing more than big chunks of whatever for the most part. Isolation and tone seem to be the only concerns. That and marketing hype.